title: The effect of aging on IgD receptor expression by T cells and its functional implications.
abstract: Exposure to oligomeric or aggregated (a), but not to monomeric (m), IgD causes a rapid (within 1 h) upregulation of IgD-R expression on CD4+ T cells from young, but not from aged, mice and on both CD4+ and CD8+ T cells from all young and from approximately 65% of aged humans. In normal young (but not in IgD-/-) mice, this increase in IgD-R expression is associated with a marked increase in primary and secondary antibody responses, transferable to both aged and young mice with T cells from aIgD pretreated donors. In both species, immunization causes a rise in the IgD-R+ expression in vivo in the young. In mice, mIgD abolishes both the induction of IgD-R expression and augmentation of immune responses, suggesting that interaction between IgD-R+ T and IgD+ B cells is needed. In aged humans, the ability of peripheral blood lymphocytes to exhibit IgD-R expression in response to aIgD in vitro or to influenza vaccine in vivo is strongly correlated to the individual's ability to produce antibody. In T cells from aged mice, but not from aged IgD-non-responder humans, IgD-R are able to come to the cell surface if an additional signal has been supplied, such as by (ionomycin/thapsigargin + aIgD). Agents which induce IgD-R and augmentation of antibody production in aged and young mice include phosphatidylcholine and dehydroepiandrosterone sulfate. The immunoaugmenting effect of pretreatment with these agents appears indeed due to IgD-R+ T cells, because it is abolished by mIgD.
authors.affiliation: Program in Immunology, Memorial Sloan-Kettering Cancer Center, New York, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Swenson
authors.forename: G J
authors.initials: GJ
authors.lastname: Thorbecke
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D006801:Humans; D007072:Immunoglobulin D / Q000276:immunology*; D051379:Mice; D011961:Receptors, Fc / Q000096:biosynthesis / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D014611:Vaccination
chemical_list: D007072:Immunoglobulin D; D011961:Receptors, Fc; C050855:immunoglobulin D receptor